1. Field of the Invention
This invention relates to an optical communication system and, more particularly, an optical communication system which includes a current buffer and a transimpedance amplifier (TIA), and uses grounded coplanar waveguide (GCPW) to be the transmission lines.
2. Description of the Prior Art
With the rapid development of Web application and the information industry, human's demand for the speed and the amount of signal transmission explode. However, because the traditional transmission medium is copper coaxial cable, the electronic signal transmission has their physical limitations. The higher the transmission speed, the more serious signal attenuation and signal distortion. Therefore, due to reduce production costs, provide better transmission quality, the optical signal with very low decay rate (<0.5 dB/km) and the characteristic of almost free from outside interference, the optical communication system with composition of the optical fiber has been widely used in all levels of the network.
The optical communication system used in data transmission between chips or in the chip becomes a topic attracted much attention in recent years. Over the past three decades continued to reduce (scale down) the CMOS integrated circuit technology into the nanometer generation stably. At the same time, the signal transmission speed cannot catch up with the rapidly rising data transmission needs in the chip or between chips when using the metal wire as the medium of electronic links. Therefore, the limitation has become one of the topics that must be addressed in the development of next generation process.
In the traditional optical communication system, the signals in the current buffer, the transimpedance amplifier (TIA) or other circuit elements are transmitted by microstrip line or coplanar waveguide (CPW). However, the transmission lines as described are not satisfactory, so there are many questions of cross coupling and substrate depletion in the signal transmission of the traditional optical communication system.